Generally, social network services (SNS) provide the following three functions.
First, the SNS provides a network or networking function that enables a user to have relationships with other users and maintain and manage the relationships. Second, the SNS provides a communication function that enables users to exchange messages. The users may have public, semi-public, and private communication with each other. Third, the SNS provides a media sharing function that enables media objects, such as photos, music, and music videos, to be shared based on the SNS, and also, conversations about the media objects account for a great part thereof. In this respect, the SNS can be regarded as functioning as a networking platform, a communication platform, and a media platform.
Meanwhile, recently, an instant message service has been commercialized. The instant message service enables acquaintances to exchange instant messages and thus instantly share information in a mobile and online environment using the SNS functioning as the communication platform.